From: Christoph <chr_news@...>
Date: 2002-09-24T03:58:41+09:00
Subject: Re: self as method argument revisited


<dblack@candle.superlink.net> wrote in message
news:Pine.LNX.4.44.0209230935140.7789-100000@candle.superlink.net...
> Hi --
>
> On Mon, 23 Sep 2002, Christoph wrote:
>
> > "Christoph"  wrote
> > ....
> > > class DBDB  # 1.7 version
> > >    class Row
> > >       ...
> > >       @row_class = self
> > whops  that should have been;-)
> >
> >         @db =   nil
>
> Sorry, I misquoted this post in my last answer.  But why do you need
> to set this to nil?

I guess pure esthetics - the  RC (ruby correct) solution
might be

class DBDB
    class Row
        classs << self
            def db
                if equal? Row
                    raise ArgumentError, "Abstract Row class ... "
                 else
                     @db
                 end
              end
              attr_writer :db
              ....
end

Anyway I think it is a very interesting approach ... I guess
it should be possible to pack  the clone,dup, inherited whatever
headache into an extension ...


/Christoph